Interactive multimedia computer programs (IMCPs) show promise as a way of delivering personally tailored (PT) information to enhance cognitive mediators of health behavior and improve patient outcomes. However, it is unclear whether PT IMCPs can be deployed in primary care offices to increase cancer screening uptake and eliminate ethnic disparities in uptake by providing PT information in each user's preferred language. Aims/Hypotheses: We will compare changes in CRC screening cognitive mediators (self- efficacy, perceived barriers, and readiness) and uptake resulting from an IMCP PT to enhance the key cognitive mediators and targeted to patients' self-identified ethnicity - with changes resulting from a non- tailored electronic leaflet control IMCP. The experimental and control IMCPs will each be offered in English and Spanish versions. We hypothesize that, compared with the appropriate control condition (English, Spanish, or both combined): (1) the English version of the PT IMCP will enhance the cognitive mediators of CRC screening behavior for English-speaking Hispanics and non-Hispanics; (2) there will be similarly favorable changes in these mediators for Hispanics using the Spanish version of the PT IMCP; (3) deployment of the PT IMCP will provide evidence of elimination of disparities in CRC screening between Hispanic and non-Hispanic subjects via its relative impact on the cognitive mediators in these groups; and (4) the PT IMCP (English and Spanish combined) will increase CRC screening uptake in Hispanics and non-Hispanics (considered separately) via changes in the cognitive mediators. Methods: Randomized controlled trial of 2 groups, comparing a PT (to the cognitive mediators) CRC screening IMCP offered in both English and Spanish versions and deployed before a primary care office visit with a non-tailored electronic leaflet CRC screening IMCP (control) also offered in both English and Spanish. Screening methods targeted will be fecal occult blood testing, flexible sigmoidoscopy, and colonoscopy. Primary outcomes will be CRC screening uptake, self- efficacy, perceived barriers, and readiness. Implications: Our findings will determine whether an IMCP that is PT to cognitive mediators of screening behavior and deployed in primary care offices prior to previously scheduled visits can activate patients of various ethnicities to undergo CRC screening. They may also suggest a promising, portable method of reducing disparities in CRC (and other) screening uptake between Hispanic and non-Hispanic individuals. PUBLIC HEALTH RELEVANCE: Our findings will determine whether an interactive multimedia computer program that is personally-tailored to cognitive mediators of screening behavior and deployed in primary care offices prior to previously scheduled visits can activate patients of various ethnicities to undergo colorectal cancer screening. They may also suggest a promising, portable method of reducing disparities in colorectal cancer (and other) screening uptake between Hispanic and non-Hispanic individuals.